Animal glue, hide trimmings, rendered fatty tissue, hair, feathers, hoofs, horn and the like comprise a potentially valuable source of such inedible proteins as collagen and alpha-keratin. However, the presence of both acidic and basic reactive side chains in the molecular make-up of these low-grade protein products complicates the chemistry of their commercial utilization. Nevertheless, it has heretofore been proposed to convert these products into surfactants by means of direct condensation with fatty acids. However, the direct condensation of proteins and fatty acids under high temperature conditions, as disclosed by Anderson el al in U.S. Pat. No. 2,164,284 has been found to result in compositions of effective surfactancy but having unacceptably dark color and offensive odor. As suggested by Sokol in U.S. Pat. No. 4,234,475 the latter problems may be diminished by carrying out the elevated temperature reaction in an oxygen-free, inert gas atmosphere. Sokol also teaches that causing the direct-addition reaction to take place in a solvent is of no particular advantage. Regardless, the costs of both providing an inert gas atmosphere and heating the reaction milieu to high temperature militates against commercial acceptability of the prior art direct condensation procedures.